[morgal48]

You will be disappointed if you are using the factory amp with a new head unit. The channel to the door speakers has an internal low pass filter that will remove frequencies above 50 Hz or thereabouts. It is possible to disassemble the Haes 6-ch and "remove" the filter. The procedure for that is on Rennlist, I think. There are also schematics for the mods necessary to the door cards to accommodate 6.5" speakers on Rennlist. Not enough room for 8", but some have installed 6 X 9. Good luck.